Abstract: The present invention relates to a method for verifying the ability of an aircraft to attain an endpoint from a starting point, comprising the steps of supplying an external evolution context of the aircraft, supplying an internal evolution context of the aircraft; calculating a trajectory of the aircraft between the starting point and the endpoint according to the external evolution context and the internal evolution context of the aircraft and according to a predetermined strategy for circumventing three-dimensional obstacles and associating an endpoint attainability state. When there is at least one trajectory between the starting point and the endpoint, the method further comprising a step of estimating a surplus of energy of the aircraft at the endpoint of the calculated trajectory.